Piston-type pump for use with highly viscous fluids



Jan. 13, 1970 HUFF'SMITH, SR

PISTON-TYPE PUMP FOR USE WITH HIGHLY VISCOUS FLUIDS Filed July 10, 1968INVENTOR Charles S. Huffsmirh,Sr.

BY I /QMW 9' 0% ATTORNEYS United States Patent 3,489,099 PISTON-TYPEPUMP FOR USE WITH HIGHLY VISCOUS FLUIDS Charles S. Hulfsmith, Sr.,Metuchen, N.J., assignor to Wood Industries, Inc., Plainfield, N.J., acorporation of Virginia Filed July 10, 1968, Ser. No. 743,718 Int. Cl.F04b 21/04, 21/08; B67d /50 U.S. Cl. 103-178 5 Claims ABSTRACT OF THEDISCLOSURE A pump for highly corrosive and viscous fluids having ahousing adapted to be submerged in a bath of fluid, a piston verticallyslidable in the housing, check valve means on the piston controllingflow of fluid into a pressure chamber of the housing and side ports inthe housing through which fluid may flow into the pressure chamber andinto and out of the housing to agitate the bath as the piston moves.

BACKGROUND OF THE INVENTION This invention relates to a pump and morespecifically to a positive displacement pump for pumping a highlyviscous, corrosive fluid.

Many industries have need for a positive displacement pump that willmeter and pump a highly viscous fluid. For example, in the newspaperindustry, offset plates are developed using a developer fluid which iscorrosive with many metals and which is very viscous, bothcharacteristics of which make the developer fluid difficult to pump. Itis desirable when pumps are used that they be made with a minimum ofmoving parts in order to keep the expense of manufacture and repair at aminimum. It is further desirable that the pump unit be capable of readydisassembly for cleaning. It is also a desirable feature that thecapacity of the pump be easily and accurately varied in order thatdelivery of the pump will be varied.

It is therefore an object of my invention to provide for a pumpconstruction which will meet the aforementioned requirements. Broadly mypump comprises a pump housing adapted to be submerged in a bath ofhighly viscous fluid. The pump housing has a plurality of ports spacedvertically in the side wall of the housing which are adapted to beclosed by the side walls of a piston which is movable vertically withinthe housing. The piston in turn has a side port adapted to communicatewith the ports in the housing and with an end port in one end of thepiston. A moveable check valve means is connected to the piston and isadapted to close the end port upon the down stroke of the piston and toopen the end port upon the up stroke of the piston. The bottom of thepiston forms a pressure chamber with the bottom of the housing such thatas the piston moves on its down stroke, fluid within the pressurechamber will be ejected there from while at the same time fluid will becaused to flow into and out of the ports in the housing whereby the bathof fluid is agitated. During the up stroke of the piston, the checkvalve means opens allowing fluid to flow into the pressure chamberthrough the ports in the housing and the ports in the piston. Means areprovided for varying the stroke of the piston in order to vary the pumpcapacity and the piston itself is made of a material having lubricantproperties and which is non-corrosive to the material being pumped.

DESCRIPTION OF THE DRAWINGS FIGURE 1 is a partial cross-sectional viewof a pump constructed according to --my invention wherein the piston isshown on the up stroke; and

3,489,099 Patented Jan. 13, 1970 DETAILED DESCRIPTION OF THE PREFERREDEMBODIMENT Referring to FIGURE 1, there is illustrated a sump 1 of afluid system in which a pump housing 2 is submerged. Housing 2 has anipple 3 on the bottom end thereof extending through the bottom of thesump and to which a nut 4 is screwed to hold the housing in the sump.

A piston 5 is slidable within the housing and is preferably made of aplastic material having lubricant properties, as for example Teflon, aproduct of the Du Pont Corporation. Use of such material also minimizesany corrosion that might occur since it is chemically and physicallyinert to many solutions.

The housing has first and second ports 6 and 7 in the side walls thereofwith the ports being vertically spaced while the piston has a port 8which is of suflicient length to overlap ports 6 and 7 as shown inFIGURE 1. The piston is also provided with an end port 9 at its bottomend which is in communication with port 8.

Port 9 is adapted to be closed by a moveable check plate 10 which ismoveably mounted on the piston by means of pilot rod 11 which extendsthrough passage 12 of the piston. The end of the pilot rod opposite thecheck plate end has an enlarged head 13 which prevents the rod fromfalling through the piston and to limit movement of the plate away fromport 9.

A pressure or pumping chamber 14 is formed between the bottom of thepiston 5 and the bottom of the housing and has on opening 15 in thebottom thereof leading to the nipple 3 on which a conduit may beconnected to lead to the area where the fluid is to be pumped.

The piston 5 has a piston rod 16 pivotably connected to the upper endthereof by a pin 17. The other end of the rod 16 is mounted in a rodhousing 18 which is pivotably connected by a pin 19 to a powered rotaryshaft 20. The effective length of the rod 16 may be varied by looseningscrews 21 on the housing so that the rod may be moved in or out of thehousing. Varying the length of the rod will in turn vary the capacity ofthe pump which is determined by the downward movement of the piston fromthe position shown in FIGURE 1 to the limit of its downward stroke asshown in FIGURE 2, If the capacity of the pump is to be increased, theeffective length of the piston rod is increased.

The operation of the pump is as follows. As the piston moves on its upstroke as shown in FIGURE 1, the check plate 10 will move downward underthe pressure of atmospheric pressure and of the fluid pressure withinthe sump 1 above the level of the plate. Fluid will then flow into thehousing through port 7, into port 8 and thence through port 9 into thechamber 14. Any liquid trapped in the housing on the top of the pistonwill fiow through the upper port 6 as the piston rises until the sidewalls of the piston close the port. This flow out of port 6 assists inagitation of the fluid Within the sump.

On the down stroke of the piston, the piston will move down to contactthe check plate which is held in position by reason of its resistance tomove in the fluid within the housing. On the initial portion of the downstroke, fluid is forced through both ports 6 and 7 which assists inagitation of the fluid within the sump. When the bottom part of thepiston reaches the point shown in FIGURE 1 at which the pressure chamberis sealed from the port 7, fluid will begin to be ejected from thechamber 14.

The piston and housing assembly may readily be disassembled for cleaningand repair. The piston rod merely has to be loosened from the rodhousing whereby the piston and rod may then be lifted from the pumphousing. The check plate assembly may be easily disconnected from thepiston by screw 11' which is threaded on the end of the rod 11. Thehousing itself may be readily disassembled from the sump by looseningscrew 4.

No packing or sealing rings are necessary in the pump construction shownsince the piston comprises a plastic having lubricating qualities. Afurther advantage of having the piston made of such a plastic materialis that there is no danger of damage to the pump in the event that itruns dry since there is no need for the liquid being pumped to provideany lubricating function.

It is apparent that because of the positive displacement action of thepiston moving in a pressure chamber and also because of the large portsutilized, that the pump may handle fluids having a variety ofviscosities. Further,

housing adapted to be submerged in a bath of viscous V fluid, a moveablepiston having a vertical stroke within said housing and forming apressure chamber with the bottom of the housing, first and second portsin the side wall of said housing wherein said first ports are positionedabove said second ports, a side port in the side wall of said pistonadapted to communicate with said first and second ports when said pistonis at the upper part of its stroke and to be sealed by the side walls ofsaid housing when the piston is at the lower part of its stroke, an endport in the end of said piston in communication with said side port andadapted to communicate with said pressure chamber, and moveable checkvalve means carried by said piston adapted to close said end port duringthe down stroke of the piston and to open said end port on the upperstroke of the piston whereby fluid will flow into said pressure chamberthrough said end port, side port and first and second ports when saidpiston is moving on its up stroke and whereby fluid will flow into andout of said first and second ports on the down stroke of said piston toagitate fluid in the bath.

2. A pump according to claim 1 wherein said piston is connected by apiston rod to a rotary shaft and said piston rod is adjustable in lengthto vary the stroke of the piston within the housing and thus thecapacity of the pump.

3. A pump according to claim 1 wherein said check valve means comprisesa check plate connected to said piston by means of a pilot rod whichextends through and is moveable with respect to said piston and whereinsaid pilot rod has means thereon for limiting its movement with respectto said piston.

4.,A pump according to claim 1 wherein said piston is made of a plasticmaterial having lubricant properties.

5. A pump according to claim 1 having means on the housing to positionthe pump within a sump of a fluid system.

References Cited UNITED STATES PATENTS 326,409 9/1885 De Volin 103-178815,301 3/1906 Manzel 103-37 1,180,221 4/1916 Adams 222385 1,455,2355/1923 Townsend et a1. 103-178 2,503,478 4/1950 Grime 222385 1,699,194.1/1929 Junkers 103154 1,849,490 3/1932 Junkers 10337 3,059,586 10/1962Brailsford 103-216 3,125,004 3/1964 White 1031 14 3,396,873 8/1968 Nef222-385 HENRY F. RADUAZO, Primary Examiner US. Cl. X.R.

